Tesla Powerwall 2 My 1st weeks experience

Originally posted by BIGSKY9 ↑

I have had the Powerwall 2 for over a week now and
so far all I can say is that is has lived up to, or exceeded
my expectations.

It is connected up to my 5.2 KW solar system and since
its commissioning it has allowed our home to run on
solar and battery only and put 20kw back into to grid
for the week.

The solar system was installed earlier this year and
installed for the PW2 to be added when available.

The solar system was a high end system and the total
cost for both solar and battery was just under $18K, which
is pretty close to the system being economically viable
at todays electricity prices IMO, and that will probably be
more viable going forward.
You also get the feature of blackout protection and a
UPS like for short power dropouts, which does not happen
that often, I admit, but its there non the less

I did initially want the DC version, but Tesla only brought
the AC version here, IMO the DC version would have been
better for supporting the whole grid, in times of need, and
I did get an inverter on the solar system that would have
supported the DC version, anyway you can tick a box when
registering the system that allows Tesla to empty my battery
to support the grid in times of need, I did tick this box

This is my little bit to help support the grid now that
Hazelwood is closed, its not all about economics IMO,
but this could prove economically positive as well as
environmentally friendly in the longer run

cheers grant

Expand

Why would the DC version be any better for supporting the grid. Surely the only difference between the AC and DC Powerwall is an inverter and since all batteries are DC and the grid is entirely AC in Australia an inverter has to be employed there somewhere. The essential requirement to support the grid in "times of need" is the ability for the electricity supplier to be able to switch the battery on or off. It won't be Tesla emptying your battery, but their software would allow the power retailer to draw it down, hopefully at a higher rate than the current FIT.

IMHO this should be in conjunction with an owner determined price/level of charge matrix so you can say "if my battery is above 90% charge I am willing to sell my power back to the grid for less than the standard retail price say 20c kWh" (Obviously if the battery is 100% charged and the panels are producing more power than I am using I have to accept the current FIT for the excess). If it is between 30% and 90% I am willing to sell for a bit more than the standard price say 35c kWh, if the charge level is between 10% and 30% the electricity retailer wants my power they will need to pay me 45c kWh but the last 10% of my battery charge is not for sale because as it is my insurance against blackouts.

There may be weeks or months where the electricity retailer doesn't want any of your power at the prices you are asking, but you will still be able to use the power yourself at night effectively valuing it at the retail price and even if you don't use the full DOD of the battery (which sacrifices some potential income) your battery will last longer. The price/charge matrix could be user adjusted on a seasonal, weekly or daily basis depending on supply/demand levels.

Q